The Kishwaukee Water Reclamation District (KWRD), serving residential, business and industrial users in and around the city of DeKalb, including over 21,000 users at Northern Illinois University, set a goal of becoming energy neutral by 2025.

With KWRD’s net-zero energy plan, the district aims to produce as much or more energy than they consume. This plan aligns with KWRD’s mission to protect public health and the environment by providing wastewater collection, treatment and disposal services efficiently and economically. Energy is a major consideration for wastewater treatment plants, as operating equipment 24/7 requires significant electricity. For KWRD, energy consumption is the second-largest expense in their overall budget.

A crucial part of the net-zero energy plan involved installing two combined heat and power (CHP) generators to power the wastewater treatment facility.

NISSEN energy contributed to solving KWRD’s challenge by providing two NPM 375 generators, which transform biogas produced during the sewage treatment process into electricity. Each generator supplies 375 kW of electricity and 462 kW of heating.

In 2020, the first CHP generator was installed, reducing the facility’s power consumption by 60 percent. However, it couldn’t meet the entire energy demand. To produce enough biogas for a second generator, the facility started processing food waste and restaurant grease, diverting these materials from landfills and generating the necessary gas volume for a second generator.

Originally, the district planned to utilise the extra biogas by 2025, coinciding with the completion of the second CHP generator installation. However, two years ago, during a meeting with Facebook (now Meta) officials regarding the wastewater needs of Facebook’s DeKalb data center, KWRD officials mentioned their energy neutrality goal. Facebook Meta offered a donation which, combined with a grant from the Illinois Clean Energy Community Foundation, enabled the second generator to come online years ahead of schedule.

In February 2022, KWRD activated the second CHP generator at the wastewater treatment facility in DeKalb. After a year of planning, this new generator joined the first one, which had been operational since 2020.

The two generators, powered by biogas produced from the wastewater treatment process, now supply 125 percent of the facility’s electrical energy needs. Surplus energy is offered free of charge to the citizens in DeKalb at six vehicle charging stations